Polybenzoxazole (PBO) polymers are used as stress buffer coatings and as interlayer dielectric materials in the fabrication of microelectronic devices and packages. Stress buffer coatings are coatings applied as the top layer of microelectronic devices such as memory chips in order to mitigate stress related reliability problems in the function of packaged devices. As interlayer dielectric materials, PBO polymer layers function as dielectric coatings that provide electrical isolation between metallic conductors that are located in the same wiring plane, between wiring planes located above or below the PBO layer, or between metallic conductors passing through the PBO layer that are connected to metallic conductors positioned above or below the PBO layer.
For reasons of processing efficiency and high productivity in the manufacture of microelectronic devices, microelectronic lithography processes require reproducible performance from photoimageable materials. Photospeed, as measured by the energy dose needed for optimal processing, is one of the important lithography parameters requiring a high degree of reproducibility. Thus, the coating composition must have a high degree of batch-to-batch photospeed reproducibility.